Snowmobile ski and blade construction

ABSTRACT

A blade for a snowmobile ski which consists of a narrow vertically disposed blade body adapted to be mounted on the longitudinal edge of a snowmobile ski in a position to depend downwardly. The forward portion of the blade curves upwardly to conform to the front of the ski. The blade is preferably provided with an integral horizontal web that is bolted or welded to the edge of the ski and lies in a abutting face to face relationship with the ski.

I United States Patent 1151 3,675,939 Vik 1451 July 11, 1972 [54]SNOWMOBILE SKI AND BLADE 3,545,560- 12/1970 Fox ..l80/5 TI CONSTRUC 0NFOREIGN PATENTS OR APPLICATIONS [72] Invent New Bnghmn' 396,225 1/1909France ..280/2l [73] Assignee: Dempco, Inc., Minneapolis, Minn.

Primary ExaminerRichard J. Johnson [22] F'led: March 1970 Armrne\'.lames V. Harmon .1211 Appl. No.: 15,603

. [57] ABSTRACT 52 us. c1. ..280/28, l80/5 R A blade for a SnowmobileSki which consists of a narrow veni- 51 Int. Cl ..B62m 27/02 Callydisposed blade body adapted to be mounted on 58 Field of Search ..1s0 5-280/21 25 26 2s Eimdinal edge a snwmbile ski in a depend downwardly. Theforward portion of the blade curves upwardly to conform to the front ofthe ski. The blade is [56] Rem-ems Cl ed preferably provided with anintegral horizontal web that is UNITED STATES PATENTS bolted or weldedto the edge of the ski and lies in a abutting face to face relationshipwith the ski. 3,252.533 5/1966 Aeder ..l80/5 1,957,372 5/1934 Thompson..280/28 3 Claims, 4 Drawing Figures PATENTEDJUL 1 1 1972 3, 675 939 sum1 BF 2 I N VEN TOR. AlbaM M VI r ATTORNEY PATENTEDJUL 1 1 I972 SHEET 2OF 2 I N VEN '1' OR.

Al baM I\A.V|K

s q w s ATTO'QAIQY SNOWMOBILE SKI AND BLADE CONSTRUCTION The presentinvention relates to the steering of motor powered snow vehicles and toskis for such vehicles.

Almost all snowmobiles now being manufactured and sold employ a pair ofskis at the front of the vehicle for steering. On a moderately slipperysurface the skis have a tendency to allow the vehicle to slide or skidstraight ahead even when the handle bars and skis are in the positionfor a full turn because of the weight of the vehicle and the large sizeof the track surface in engagement with the snow. To overcome thisproblem the invention has as its object the provision of an improvedsnowmobile and ski having the following characteristics and advantages:a) the ability to enable the vehicle to turn on a reduced turning radiuswhen traveling over slippery packed snow or ice; b) the provision of anadded margin of safety by allowing improved steering control; c) a meansfor improving engagement between the ski and the snow when the vehiclemakes a turn without increasing drag when the vehicle is not in a turn;d) the strengthening of the ski.

In the figures,

FIG. 1 is a perspective view of a snow-mobile embodying the invention.

FIG. 2 is a front elevational view of a ski.

FIG. 3 is a plan view ofa ski, and

FIG. 4 is a perspective view ofa ski.

Briefly, the present invention provides a snowmobile having a vehiclebody with propulsion means thereon and a steering ski mounted forturning about an inclined axis. The ski is pro-- vided with a dropcenter and at least one longitudinally extending laterally locateddownwardly depending steering blade is positioned on the side edge ofthe ski with its lower longitudinally extending edge located somewhatabove the elevation of the drop center part of the ski.

In the F IGS., the snowmobile includes the usual vehicle body 12,propulsion system 14, of which only the track can be seen, and a pair ofski supporting and steering shafts l6 and 18 mounted for pivotalmovement upon axes that are parallel to one another and inclined suchthat their lower ends are located forwardly of their upper ends. Theshafts l6 and 18 are secured as by welding at 20 and 22, respectively(FIGS. 3 and 4) to tubes 24 and 26 mounted upon U shaped brackets 32 bypivot pins 30.

It can thus be seen that the position of the inclined steering shafts l6and 18 will cause the skis mounted at their ends to tilt to the sidewhen the shafts are turned by the handle bars.

Since the left and right skis are identical, only one will be describedin detail.

Each U shaped bracket 32 includes parallel side portions 320 and 32b.Rigidly affixed to the lower surface of bracket 32 is a leaf spring 34having its forward and rearward ends 340 and 34b respectively secured tolaterally disposed pivots 36 and 38 which are supported upon brackets 40and 42, respectively. Both of the brackets 40 and 42 are secured to thebody of the ski 44 preferably by welding.

The ski 44 includes a pair of flat longitudinally extending coplanarside sections 46 and 48 which are co-extensive with a rear section 49that is slightly upturned as seen in FIG. 4. The forward portions 46aand 48a of the side sections 46 and 48 respectively bend upwardly todefine the forward part of the ski. The tip support comprising the steelrod 50 bent to the general form of a letter J is welded between thebracket 40 and the ski tip 52 to strengthen the front end of the ski andprovide a handle.

The middle portion of the ski is provided with a trough or drop center54, as best seen in FIGS. 1, 2 and 4. The drop center 54 extendslongitudinally the full length of the ski, including the upturnedforward portion defined by portions 460 and 48a but does not extend intothe upturned portion 49.

A longitudinally extending rod 56, only a portion of which can be seenin FIGS. 1 and 2, is welded to the lower surface of the drop center 54and extends the entire length of the ski to provide the ski with greaterresistance to wear and abrasion.

As best seen in FIG. 2, the drop center portion 54 supports the otherparts of the ski, including the side sections 46 and 48 a substantialdistance above the surface of the snow 60 under hard packed conditions.

The steering blades in accordance with the invention will now bedescribed.

Each ski 44 is provided with a pair of steering blades comprising theleft and right steering blades 62 and 64. The blades 62 and 64 can beused either two to a ski or one to a ski. Each of the left blades 62 areidentical, as are each of the right blades 64. Each left blade 62consists of a vertically disposed longitudinally extending web 66 whichis the functional portion of the blade and an integral horizontallydisposed web 68 secured at longitudinally spaced intervals to section 46of the ski by bolts 70 or other suitable fasteners.

Both of the webs 66 and 68 bend upwardly the forward portion of the skito conform to the upturned section 46a. It should be noted that the web66 is located near the lateral edge of the ski and that its lower edge72 is at a higher elevation than the lower edge of the drop center 54.This provision insures that the web 66 will not contact the ground whenthe skis are running straight ahead over a hard surface.

The right blades are constructed in a similar manner, includinghorizontal and vertical webs and 82 respectively. secured to thehorizontal sections 48 by bolts or other suitable fasteners 84. Bothsections 80 and 82 bend upwardly to conform to the forward portion ofthe ski. The lower edge 86 of web 82 is at a proper elevation to remainout of contact with the ground or hard packed snow 60 when the dropcenter rests on the ground.

Refer now to FIGS. 1 and 2 with regard to the manner in which the bladesoperate when the vehicle is in use. As shown in FIG. 2, the blades 62and 64 are out of contact with the snow when on a hard surface if in anupright vertical position. Whenever the vehicle is engaged in a turn asshown in FIG. 1, owing to the angle of inclination of steering shafts l6and 18, the skis 62 and 64 will tilt or cant to one side such that whena left turn is being negotiated, their left lateral edges will be lowerthan their right lateral edges.

Thus, as seen in FIG. 1, the right ski edges and blades 64 would beraised enough to be partially or entirely out of engagement with thesnow 60 when a left turn is being made and a substantial portion of theweight of the vehicle will be transferred to the blades 62. Accordingly,the blade 62 will provide a highly effective engagement with the snowand enable the vehicle to turn on a radius that is virtually the same asits theoretical turning radius even when traveling at a high speed andin this way very effectively prevent the vehicle from side slipping aswell as providing better steering control. Similarly, when the vehicleis making a right turn, blade 64 will be engaged with the snow and blade62 will be elevated above the surface of the snow.

In summary, this invention makes possible sharp turns on hard packedsnow or on ice as well as improving the steering control that can beobtained by the operator. Because blades 62 and 64 have their loweredges spaced above the elevation of drop center 54, they do not contactthe ground and increase drag on the vehicle traveling straight ahead.Since the webs 66 and 82 are spaced relatively far apart, snow does nottend to compact between them.

If the skis are made of 16 gauge steel, blades 62 and 64 made of 12gauge steel have been found suitable. Since most snowmobile skis aremade of 16 gauge steel, it will be seen that the blades strengthen theski substantially. The upwardly curved portions at the forward ends ofthe blades prevent damage by stones or other obstructions. While thedimension of the blades can be varied considerably, several hundredunits in which the webs 66, 82 had a height of three-quarter inchperformed admirably for extended periods of time.

I claim:

1. A substantially straight snowmobile ski having a flat normallyhorizontally disposed elongated body formed from sheet material with anupwardly curved forward portion, a longitudinally extending drop centersupporting surface extending longitudinally of the ski and having alower surface substantially below the lower surface of the lateral edgesof the ski body, at least one longitudinally extending verticallydisposed blade member fixedly positioned in the vicinity of one lateraledge of the ski and depending downwardly therefrom, said blade extendingforwardly to substantially the forward tip of the ski and rearwardlyalong a major portion of the length of said ski, and having a lower edgepositioned at a higher elevation than the lower surface of the dropcenter portion, the forward portion of the blade being curved upwardlyto conform to the front upwardly curved portion of the ski body.

2. The combination of claim 1 wherein a normally horizontally disposedweb of sheet metal is integral with the blade body and extends at rightangles thereto from the upward edge thereof toward the ski center, saidweb being adapted to be secured in face to face abutting relationshipwith the edge of the ski and thereby support the blade.

3. The snowmobile ski of claim 1 wherein said blade includes ahorizontally disposed web integral with the vertically disposed blade,said web being rigidly affixed to the ski and being positioned in a faceto face abutting relationship therewith.

1. A substantially straight snowmobile ski having a flat normallyhorizontally disposed elongated body formed from sheet material with anupwardly curved forward portion, a longitudinally extending drop centersupporting surface extending longitudinally of the ski and having alower surface substantially below the lower surface of the lateral edgesof the ski body, at least one longitudinally extending verticallydisposed blade member fixedly positioned in the vicinity of one lateraledge of the ski and depending downwardly therefrom, said blade extendingforwardly to substantially the forward tip of the ski and rearwardlyalong a major portion of the length of said ski, and having a lower edgepositioned at a higher elevation than the lower surface of the dropcenter portion, the forward portion of the blade being curved upwardlyto conform to the front upwardly curved portion of the ski body.
 2. Thecombination of claim 1 wherein a normally horizontally disposed web ofsheet metal is integral with the blade body and extends at right anglesthereto from the upward edge thereof toward the ski center, said webbeing adapted to be secured in face to face abutting relationship withthe edge of the ski and thereby support the blade.
 3. The snowmobile skiof claim 1 wherein said blade includes a horizontally disposed webintegral with the vertically disposed blade, said web being rigidlyaffixed to the ski and being positioned in a face to face abuttingrelationship therewith.